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徐宝林 《计算机应用与软件》2011,28(7)
在三层结构中,应用程序访问后台数据库数据是最重要的环节,而应用程序访问后台数据是通过调用类方法来实现的.很显然,类方法实现的是模块功能,所以,在设计类方法之前必须研究清楚应用程序访问后台数据库数据的模块划分.通过对应用程序访问后台数据的典型访问模式及实现研究,得出了应用程序访问后台数据模块划分的普遍规律. 相似文献
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实时数据采集和管理系统中的DLL和DDE技术 总被引:5,自引:1,他引:4
本文描述了在实时数据采集系统中,利用DLL技术实现在VFP中调用C程序的方法,以及利用DDE技术实现前台数据采集应用程序与后台数据库管理系统之间的数据传递。 相似文献
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Web站点构造中的ODBC技术应用 总被引:1,自引:0,他引:1
基于Web站点制作过程中的数据库调用问题,讨论了在客户端与服务器之间进行数据的传送与处理的相关技术,探讨了利用ODBC技术解决有关Web站点的数据库调用问题的方案,给出了ODBC的应用细节及一般解决步骤。 相似文献
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本论文主要论述小型饭店管理信息化的设计与实现,系统使用VisualBasic(VB)作为前台开发工具,Access作为后台数据库,利用ADO技术来访问数据库。用户可以通过界面操作调用应用程序,利用ADOData控件快速地创建一个应用程序到数据库的连接,利用界面操作方式来更新和修改数据库中的表、实现点餐结帐等功能。 相似文献
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基于ADO技术动态创建SQL Server数据库 总被引:3,自引:0,他引:3
为了保存程序运行过程中产生的临时数据,比较好的做法是创建动态数据库,这既能灵活地处理各种类型格式的临时数据,又能节省存储空间。文章在Visual C++数据库应用程序中,利用ADO对象连接SQL Server数据源,然后通过调用ADO对象的函数来执行SQL语句,以动态地创建SQL Server数据库。 相似文献
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Hash和存储过程在分布式数字认证中的应用 总被引:3,自引:1,他引:3
随着网络技术发展和分布式应用程序的广泛应用,如何构建安全的分布式Web应用程序是信息安全中的一项重要内容。安全登录认证凭据的处理是分布式WEB应用程序安全的基础,为提高基于.NET的分布式应用程序的安全性,文章分析了.NET中哈希加密算法的结构,提出了利用HASH加密算法,通过ADO.NET和SQLServer数据库中的存储过程调用,实现用户登录凭据的处理,保证了WEB应用程序的安全。 相似文献
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VB环境下Oracle数据库备份同步的实现 总被引:2,自引:1,他引:2
李志伟 《计算机工程与设计》2009,30(13)
为解决VB应用程序中Oracle数据库备份问题,研究了Oracle数据库备份的一般方法,提出了利用Shell调用实现数据库逻辑备份产生的程序异步问题.分析了API接口技术对扩展VB功能的作用,通过具体的程序实例,利用API接口函数,调用Windows操作系统功能,实时检测Shell外部函数的执行情况,解决了程序进程的控制问题,实现了Oracle数据库逻辑备份的同步操作. 相似文献
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同军红 《数字社区&智能家居》2010,(12)
该文提出了一种基于MDA数据库概念模型可视化设计解决方案。使得数据库概念模型相当于MDA中的PIM模型;物理模型相当于MDA的PSM模型。概念模型和物理模型之间的相互转化可以自动完成。提高数据库设计的效率和数据库文档一致性。 相似文献
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In this paper, we firstly present a conceptual data model for multimedia database applications based on ExIFO2 model. The ExIFO2 data model is chosen as the conceptual model since it handles complex objects along with their uncertain and imprecise properties. We enhanced this conceptual model in order to meet the multimedia data requirements. In addition to uncertain and imprecise information, we present a way of handling relationships among objects of multimedia database applications. Events that might be extracted from video or audio are also considered in this study. Secondly, the conceptual model is mapped to a logical model, which the fuzzy object-oriented data (FOOD) model is chosen, for storing and manipulating the multimedia objects. This mapping is done in a way that it preserves most of the information represented at the conceptual level. Finally, in this study videos of football (soccer) games is selected as the multimedia database application to show how we handle crisp and fuzzy querying and retrieval of fuzzy and crisp data from the database. A program has been developed to draw ExIFO2 schemas and to map the schema to FOOD code automatically. 相似文献
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云环境下图数据库建模技术及其应用研究 总被引:1,自引:0,他引:1
针对云环境下传统关系型数据库在大数据库建模方面存在的诸多问题,描述了一种全新的能适应云计算环境建模的图数据库,定义了图数据库模型的基本概念,给出了图数据库建模元素及组织形式,在关系型数据库概念模型建模理论及方法的基础上提出了图数据库建模的若干规则和方法。以图数据库Neo4j为例,详细描述了现代物料入库管理图数据库的建模过程,并应用Cypher语言实现该系统模型的增加、删除、更改、查询及统计功能。实践结果表明:利用图数据库建模技术构造的模型具有语义表达更丰富、更具简易性和可扩展性等优点,对开发基于图模型的智能管理信息系统能够提供一定的参考依据。 相似文献
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关系数据库设计要求规范化处理的过程以消除数据冗余和更新异常问题. 范式化理论的算法与数据依赖有着直接的联系, 数据依赖中最重要的是函数依赖, 识别该依赖既耗时又复杂. 讨论如何在采用ER模型的数据库逻辑设计步骤中消除规范化处理过程, 在概念结构设计过程中遵循一组规则将产生满足3NF范式的初始关系模式集, 以节省数据库设计者在导出初始关系模式集后的规范化处理步骤. 相似文献
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Conceptual Data Modeling for Spatiotemporal Applications 总被引:5,自引:0,他引:5
Many exciting potential application areas for database technology manage time-varying, spatial information. In contrast, existing database techniques, languages, and associated tools provide little built-in support for the management of such information. The focus of this paper is on enhancing existing conceptual data models with new constructs, improving their ability to conveniently model spatiotemporal aspects of information. The goal is to speed up the data modeling process and to make diagrams easier to comprehend and maintain. Based on explicitly formulated ontological foundations, the paper presents a small set of new, generic modeling constructs that may be introduced into different conceptual data models. The ER model is used as the concrete context for presenting the constructs. The semantics of the resulting spatiotemporal ER model, STER, is given in terms of the underlying ER model. STER is accompanied by a textual counterpart, and a CASE tool based on STER is currently being implemented, using the textual counterpart as its internal representation. 相似文献
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海洋渔业数据库质量控制研究 总被引:5,自引:0,他引:5
为了利用可视化技术来对海洋渔业数据库进行质量控制,在综述了近年来GIS数据库质量控制的基础上,首先提出了GIS数据库质量控制的多层次概念模型;然后针对海洋渔业地理信息系统的特点,给出了海洋渔业数据库质量控制的体系结构和具体的控制方法,并在现有的元数据和数据仓库技术的基础上,提出了基于元数据的智能化控制方法原理;最后结合前人工作和国家863计划818主题的海洋渔业GIS课题研究成果,给出该质量控制的概念模型应用于海洋渔业具体的控制体系和方法。 相似文献
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In this paper, a temporal meta database for three-dimensional (3D) objects whose properties and relationships are supported
by valid time is introduced. Based on our proposed temporal object-oriented conceptual schema model, a conceptual schema of
the temporal meta database can be generated from a 3D graphical data source and other particular application requirements.
Based on our proposed temporal object relational data model with attribute timestamping, logical schemas of the temporal meta
database can be systematically and automatically generated from the conceptual schema. From the temporal meta database, non-temporal/temporal
metadata about temporal 3D objects are available for temporal information system users. Convenient access using database languages
such as SQL can be performed. Queries over 3D objects using a temporal object relational SQL are demonstrated. 相似文献
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The recent emergence of object‐relational technology into the commercial database market has caused new challenges for the implementation of conceptual database designs. This paper presents our experience with using the Oracle 8 object‐relational data model in the implementation of an engineering application described using the EXPRESS conceptual modeling language. EXPRESS is part of the engineering community's Standard for the Exchange of Product Data and can be characterized as a structurally object‐oriented modeling language, supporting the notion of entities, entity hierarchies, complex constraints on entity hierarchies, relationships and inverse relationships between entities, and user‐defined types. As a result, EXPRESS provides an excellent framework for studying the mapping of conceptual modeling concepts into an object‐relational model. In this paper, we describe the way in which the features of EXPRESS can be mapped into object‐relational features such as object tables, object references, and nested tables. We also describe the manner in which features such as member functions on object types, triggers, and stored procedures can be used to support the implementation of constraints associated with a conceptual schema. Although the mappings presented are specific to EXPRESS and Oracle 8, the mappings are generalizable to conceptual modeling languages and object‐relational models with similar features. Our work defines how traditional mapping concepts must be revised in order to make adequate use of the features now found in object‐relational models. As part of this paper, we also compare our mapping approach using Oracle 8 to mapping issues for the PostgreSQL object‐relational model and the Objectivity/DB object‐oriented data model. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
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从物理数据库恢复概念数据模型的过程称为数据库逆向工程(DBRE)。本文首先介绍了ER模型的主要构造子,然后描述了数据库逆向工程的概念和处理过程。接着分析了前期研究人员提出的多种逆向工程方法和主要CASE工具逆向工程方法的特点。 相似文献